Every year my Q4 estimated tax payment is applied to the next year Q1 tax payment because it was paid the next year, How do I adjust this to apply to the correct year?

I'm glad to have you here, Jennylyn.

Let me provide the steps on how to apply your tax payment to Q4 instead of Q1 next year.

Let's start by locating the downloaded tax payments. Then, exclude them from the Transaction page so they won't be recorded in Q1 the following year. 

Here's how:

1. Hover your cursor to Transactions. 
2. To show This year only, filter the list of transactions.
3. For Estimated Taxes, you can filter the Category Type.
4. Tap the drop-down arrow to expand transaction details.
5. Tick the box of Exclude. Then, hit Save.

After that, manually enter these transactions and ensure the date is within the Q4. Check out the steps below:

1. Go to Transactions again, then choose Add Transactions.
2. Enter the Transaction Details.
3. Ensure to utilize dates within Q4 of (Year) as the Transaction date.
4. Tap on Save.

I'll add this article as a reference in recording entries manually: Manually add transactions in QuickBooks Self-Employed.

You might want to get transactions from before you connected accounts. Feel free to read this article: Add older transactions to QuickBooks Self-Employed.

Additionally, please take a look at this article to learn more few things about managing imported and online banking entries: Categorize transactions in QuickBooks Self-Employed.

Leave a comment below if you have additional tax adjustment-related concerns in QBSE. I'll be willing to lend a hand. Keep safe and have a good one.